Utility control of domestic water heaters as a means to shed and/or shift electrical load during peak demand periods has been available for several decades. However, the effectiveness of currently deployed systems has been somewhat limited in accuracy, reliability and detail. Current systems are typically unidirectional, i.e. commands can be sent from the utility to the water heater to shut off supply power during peak load periods, but there is no upstream communications to verify that the command was received and acted upon, nor how much load was avoided. In fact, it is not unusual for power utilities to discover that the system at the customer premise has been defeated or has otherwise become non-operational. Additionally, even these legacy unidirectional control systems often require substantial capital investment to build up the required RF infrastructure (radio towers and backhaul). In light of the limitations of current water heater control systems, power utilities have been able to offer their customers only relatively small economic incentives to sign up for load shedding plans which have resulted in slow adoption rates.
In recent years, most of the developed world has seen the widespread deployment of various Wide Area Networks (WANs), from digital cellular RF networks to fiber to the home (FTTH), DSL, and broadband over cable. These networks typically feature a relatively low data transport cost. At the same time that these low cost WANs have become available, the world has seen dramatic increases in the cost of petro-fuels, concerns over the emission of CO2, and a reluctance to accept the building of new generation facilities, resulting in a major problem with supply and demand for energy. These colliding factors have created both a great need to shift utility loads to off peak hours whenever possible and the infrastructure required to manage customer side loads. Shifting load to avoid utilizing inefficient and environmentally threatening energy is the fastest path to delay the demand crossing the supply curve and to avoid the tremendous investment in new power generation facilities. Recent reports estimate the cost of a new nuclear plant to be between $9 to $14 billion.
Thus, there is a need for a system to reduce peak load, thus allowing better use of existing power plants and minimizing the need for new power plant construction.